This invention relates to a fader used in an audio mixer, a dimmer or the like and, more particularly, to a fader device in which absolute amounts of fading in respective channels can be readily recognized when fader operators of respective channels are operated as a group.
A fader is a device for changing gain continuously and is used for, e.g., an audio device such as an audio mixer for individual adjustment of signal levels of multiple channels in mixing these signals. A fader has a fader operator for each input channel and adjusts a signal level or the like individually for each channel by operation of the fader operators.
In the course of adjusting signals levels of the respective channels individually in a fader device, there sometimes occurs an excessive increase or decrease in the signal level as a whole while the relative relation of the signal level among the respective channels is maintained in a good relation and, in this case, adjustment of the signal level as a whole becomes necessary. In this case, it is extremely troublesome and difficult to achieve the desired adjustment by operating the fader operators individually while maintaining the relative relation of the signal level among the respective channels unchanged.
For overcoming this difficulty, there is a prior art fader device in which, as shown in FIG. 2, a group master fader 20 is provided aside from faders 11 to 16 for respective channels CH1 to CH6 for adjusting the amount of fading as a whole. FIG. 3 shows a circuit construction of this fader device. Input signals of the respective channels CH1, CH2, CH3 . . . are adjusted in level by the individual faders 11, 12, 13, . . . and delivered out through VCAs (voltage-controlled type amplifiers) 21, 22, 23, . . . . There is also provided an operation mode changing switch 30 for switching the fader operation manually between a single operation mode and a group operation mode. When the switch 30 is switched to the single operation mode, the VCAs 21, 22, 23, . . . all become fixed at a reference gain 0 dB and amounts of fading of the respective channels are adjusted only by operation of the individual faders 11, 12, 13, . . . . When the switch 30 is switched to the group operation mode, the VCAs 21, 22, 23, . . . are controlled commonly by the group master fader 20 to adjust the amount of fading as a whole.
According to the level adjustment by the group master fader 20 of the prior art fader device, the operation of the group master fader 20 causes amounts of fading of the respective channels CH1, CH2, CH3 . . . to be changed while fader operators 10 of the respective channels remain unmoved. Accordingly, relation between positions of the respective fader operators 10 and actually obtained amounts of fading of the respective channels is not determined so that absolute amounts of fading in the respective channels cannot be readily recognized by observing the positions of the fader operators 10. This is particularly so in a case where a plurality of groups have been provided and the amount of fading by the group master fader 20 differs from group to group.
It is, therefore, an object of the invention to provide a fader device in which absolute amounts of fading in the respective channels in the group operation mode can be readily recognized.